A DC/DC converter is a switching power supply that accepts a DC input voltage and generates a DC output voltage that is typically different from the DC input voltage. DC/DC converters include a switching transistor that is turned on and off to charge and discharge an inductor. Switching losses in the transistor may be reduced by coupling a resonant inductor-capacitor circuit to the switching transistor to produce sinusoidal rather than square-wave current waveforms. Such DC/DC converters are referred to as resonant DC/DC converters.
LLC resonant converters, which include a resonant circuit using two inductors and a capacitor, provide a number of benefits over other resonant converter architectures. For example, LLC resonant converters offer high efficiency over a wide range on input voltages and loading conditions. Synchronous rectifiers are used on the secondary side of an LLC resonant converter to improve efficiency.